Pallets are used to transport many different types of loads. A pallet may be used separately, purely as a load bearer, in order to facilitate the handling of loads in the form of one or more items. A pallet may also be used together with what is called a superstructure. The superstructure may be provided with walls, and, in this case, part of its function is that, when it is placed on top of the pallet, it delimits the loading space with its walls, which then extend around the load-bearing surface of the pallet. Awkward loads, such as small packages or loose objects, may then also be transported on the pallet. The superstructure may also be used to create an even surface on top of which a further pallet may be placed, so-called stacking. Known superstructures are usually made of wood, plastic or corrugated board.
In order to delimit the loading space at the top, a superstructure may also have a lid. This provides additional protection for the load.
One or more of the sides of the superstructure may be provided with windows to permit access to the load without having to remove the whole superstructure.
To be able to effectively transport and store pallets with their load, it is in many cases desirable to be able to stack one or more pallets onto pallets with superstructures. An upper pallet is then placed such that it is supported by the superstructure of a lower pallet. The weight of the upper pallet, and possibly of further pallets lying on top of it, is placed on the superstructure.
An example of a commonly used superstructure is a so-called pallet collar. Pallet collars often consist of a wooden frame which is provided with four hinge joints of metal in the four corners. The metal pieces that form the hinge joint are provided with downwardly and outwardly extending tongues which engage around the corners of the pallet or an underlying pallet collar. Several pallet collars stacked on top of one another provide a higher and therefore larger loading space.
A problem with pallet collars is that they are awkward to handle and difficult to store when not in use. A solution to these problems is to provide a more collapsible superstructure. There are known superstructures which are collapsible by virtue of the fact that they are provided with further hinge joints in addition to the four in the corners. These further hinge joints are placed, for example, on the two opposite short sides. In this way, the short sides may be collapsed inward and the superstructure may then be folded up such that its necessary area becomes slightly less than the surface area of the pallet. An advantage of this is that the superstructure, when collapsed, may then be placed on the pallet during transport of the pallet, after the load has been removed. However, collapsible superstructures of this known type are unable to cope with such a great load as may a pallet collar composed of a wooden frame and metal hinge joints. The reason is that the design of the collapsible superstructure with further hinge joints, and in some cases with an openable window, adversely affects the load-bearing capacity, which means that the superstructure is deformed under a lower load than is a pallet collar.
Consequently, there can be said to be a need for an improved superstructure that is easy to store and that has an improved load-bearing capacity, particularly in the event of stacking pallets with superstructures.